Book closer and Record date on SATURDAY?

If the record date is on Saturday the holding /value of Friday is taken to determine who all are eligible for bonus /rights/dividend etc but WHAT IF THE BOOK CLOSER STARTS FROM SATURDAY ? will the value of Friday be taken or thursday ?
Please note that in case of record date same date value is taken wherein in case of book closer 1 day before value is taken from book closer start date ? my question is IS IT ONE WORKING DAY BEFORE OR ONE DAY ?